This is the fifth book of the Lensmen series. The social attitudes are old fashioned, the science is outdated, and the language is florid, but it is still a great read.
This is the third book to describe the exploits of Kimball Kinnison. These books are the core of the Lensman saga. Starting with Galactic Patrol the excitment is non-stop through to the end of Second Stage Lensman.
If you like action on a grand scale, this is a must read, but start with Triplanetary, First Lensman, or Galactic Patrol first.